Improvement relating to magnetic floor sweepers



Nov. 2, 1954 w. E. BOX ETAL IMPROVEMENT RELATING MAGNETIC FLOOR SWEEPERS2 Sheets-Sheet 1 Filed April 21, 195'1- 1954 w. E. BOX ET AL 2,693,279

IMPROVEMENT RELATING TO MAGNETIC FLOOR SWEEPERS Filed April 21, 1951 2Sheets-Sheet 2- United States Patnt IMPROVEMENT RELATING TO MAGNETICFLOOR SWEEPERS William Edward Box, Erdington, Birmingham, and JohnThomas Claridge and Arthur George Turnock, Sutton Coldtield, England,assignors to Electromagnets Limited, Birmingham, England, a company ofGreat Britain This invention has reference to improvements relating tomagnetic floor sweepers. As is well known magnetic floor sweepers asgenerally constructed incorporate a cylindrical drum the outer surfaceof which serves as the collecting surface, a magnetic force producingmeans located within the drum and wheel means for enabling the drum tobe traversed over a surface from which the material is to be collectedand the present invention has for its object to provide an improvedmagnetic floor sweeper of this kind in which the removal from thecollecting surface of any collected magnetic material is facilitated.

According to the invention an improved magnetic floor Y sweeperincorporates a cylindrical drum the lowermost portion of the outersurface of which serves as the collecting surface for the magneticmaterial to be collected,

,wheeled supporting means for said drum, handle means for propelling thedrum over the floor surfacefrom which magnetic material is to becollected, magnetic force producing means located within said drum withthe magnetic poles located normally in proximity to the 1 inner surfaceof the lowermost portion of the drum,

means for turning the said magnetic ;force producing means from theposition occupied during sweeping so that any magnetic materialcollected'on the drum can follow the magnetic force producing means asit is turned and means for arresting the movement of the collectedmaterial after the magnetic force producing means has been turned to apre-determined extent so that after the collected material has reachedthe arresting position continued turning of the magnetic force producingmeans results in the collected material being subjected to a diminishingfield of force whereby the collected material is released for collectionor disposal. .The invention also resides in'magnetic separatorsconstructed and adapted for use substantially as will be describedhereinafter.

Embodiments of the invention willnow be described with particularreference to the accompanying drawings .Wherein:

Figure l is a perspective view of a magnetic floor sweeper constructedin accordance with the invention.

Figure 2 is a fragmentary view of the magnetic floor sweeper illustratedin Figure 1 showing the manner of removing the magnetic materialcollected by said sweeper.

Figure 3 is a fragmentary view mainly in longitudinal vertical sectionbut partly in front elevation of a portion ofdtge magnetic floor sweeperillustrated in Figures 1 an Figure 4 is a fragmentary sectional vviewshowing the relative disposition of the parts during sweeping thesection being taken on the plane indicated by the line 4-4, Figure .3,looking in the direction of the arrows to said line.

Figure 5 is a similar view to Figure 4 but showing the relativedisposition of the parts when the removal of any collected-magneticmaterial is being occasioned.

Figure 6 1s a front perspective view of another construct1on of magneticfloor sweeper in accordance with the invention.

Figure 7 is a rear perspective view of the magnetic floor sweeperillustrated in Figure 6 with the collecting trough for magnetic materialremoved.

Figure 8 is a fragmentary view mainly in longitudinal vertical sectionbut partly in front elevation of a portion ofdthle magnetic floorsweeper illustrated in Figures 6 an 2,693,279 Patented Nov. 2, 1954Figure 9 is a fragmentary sectional view showing the relativedisposition of the parts of the magnetic floor sweeper illustrated inFigures 6-8 during sweeping, the section being taken in the planeindicated by the line 9-9, Figure 8, looking in the direction of thearrows to said line.

Figure 10 is a similar view to Figure 9 but showing the relativedisposition of the parts when the removal of any collected material isbeing occasioned.

According to the embodiment of the invention illustrated in Figures 1-5the improved magnetic floorsweeper incorporates a pair of rubber tyredroad wheels 20 which are freely mounted on the ends of an axle 21 towhich is bolted a plurality of permanent magnets 22 which tend to hangvertically under the influence of gravity, see Figures 3 and 4.

The permanent magnets 22 aforesaid are enclosed within a close fittingconcentric cylindrical shield 23 of sheet metal which is fixed to theends of a yoke 241 constituting the lower portion of the handle 24. Theshield 23 is provided at the front with an outwardly projectinglongitudinally arranged flange 231 hereinafter I termed the stop flange231.

Rigidly connected to the end portions of the axle 21 externally of theends of the shield 23 is a pair of outwardly projecting arms 251 whichare interconnected by a bar 25 which is located in front of the shield23 and the wheels 20, said bar 25 being referred to hereinafter as thebumper bar 25.

At each end the shield 23 is provided with outwardly projecting pins 26which-co-operate with the arms 251 to serve as stop pins for supportingthe bumper bar 25 when the magnets 22 are hanging vertically.

The handle 24 may be provided with a depending strut not shown whichserves as a foot when the apparatus is at rest.

In readiness for use the bumper bar 25 rests with its arms in contactwith the stop pins 26 with the permanent magnets 22 occupying thevertical position and with the arcuate surface of the magnets 22adjacent to the inner surface of the portion of the shield 23immediately above the floor level, see Figure 4.

The apparatus may then be propelled over a floor to be swept in themanner of the usual magnetic floor sweeper.

When it is desired to remove any collected magnetic material theapparatus is held in a position of rest and the bumper bar 25 drawnupwardly thereby occasioning a turning of the permanent magnets 22 sothat the curved outer surfaces thereof move upwardly inside the fixedshield 23. The turning of the permanent magnets 22 as aforesaid causesthe collected material adhering to the underside of the outside of theshield to follow the magnetic field of force but when the traverse ofthe magnets 22 is such that the collected material strikes the stopflange 231 further movement of the said collected material is preventedso that as the magnetic field further j recedes, the collected materialdrops and may be removed as desired, see Figure 5.

When the collected material has been removed the bumper bar 25 isreleased thus allowing the'magnets 22 to resume the initial dependingvertical position.

It will be seen that the improved magnetic floor sweeper in theembodiment described dispenses with the use of the usual rotatableshield with its complications of construction and furthermore enablesmagnets of much smaller bulk to be used since it is only necessary toprovide for an intensive magnetic field at the place of collectionnamely immediately above the floor level, thus making for a materialreduction in first cost and in the weight of the apparatus as a whole.

According to the embodiment of the invention illustrated in Figures 6-10the rubber tyred road wheels 20 again are freely mounted on the ends ofan axle 21 to which is bolted a plurality of permanent magnets 22 whichtend to hang vertically under the influence of gravity.

As in the embodiment first described the magnets 22 are enclosed by aclose fitting cylindrical shield 23 of non-magnetic sheet material saidshield 23 likewise being fixed to the ends of a yoke 241 associated witha handle 24.

33b which are located at- Disposed at the rear" of the shield 23 is aremovable trough 27 of sheet metal for the reception of any collectedmagnetic material, said trough 27 being adapted to be supported by arms28 fixed to and projecting rearwardly from the ends of. the shield 23.

Associated with the arms 28 are-strut's281 which serve as feet-when thesweeper is at rest.

Fixed to the upper portion oftheshield 23 is a deflector plate 30 whichinclines downwardly and rearwardly with its lower end disposed above thetrough-27 when supported by the arms 28, see Figures 9 and 10.

Fixed to the inner side of each wheel29 is a disc 31 each of which haspivoted thereto a fingerq32 which tends to assume the pendantpositionunder the action of gravity.

Disposed on either side of the fingers'32 arepegs 33a, difierentdistances from the centres of the respective-wheels 20.

The fingers 32 co-operate with the noses 341 of cams 34 fixed to theaxle 21.

' The location of the pegs 33a, 33b is such thatwhen the apparatus ispropelled in a'forwards direction the fingers32 strike the pegs 33a andride clear of the noses 341 of the earns 34 so that a free forwardmovement is permitted see Figure 9 and such .thatwhen the apparatus isdrawn in a backwards direction, thefingers 32come into contact with thepegs 33b and with the tips of the said fingers 32 engaged with thenoses341 of the earns 34 thus coupling the road wheels 20 to the axle 21.Consequently if backwards movement is continued after the fingers 32engage the noses 341 of the axle 21 the magnets 22 are turned in aclockwise directionwhereby any collected material is carried around theshield 23 on to the deflector plate 30 and is caused to fall into thetrough 27 when the backwards movement is arrested and the magnets 22permitted to resume their vertical position under the action of gravity.

Thus when it is desired to remove the collected magnetic material fromthe collecting surface of the device, the sweeper is. drawn in abackwards direction until the tips of thesaid fingers 32 engage withthepegs 33b and with the noses .341 of the earns 34 and occasion theturning of the magnets 22 in a clockwise direction as seen in Figures 9and until the magnets 22 have been turned to an extent sufficient tobring. the collected material on to the deflector plate 30 whensubseqeunt backwards movement increases the air gap between thedeflector plate 30 and the magnets 22 so that the collected materialwhich is thus removed from the influence of the magnetic field of forceis permitted to fall down. the deflector plate 30 into the collectingtrough 27.

It will be appreciated that a magnetic floor sweeper in accordance withthe embodiment last described is simple in construction, efl'icient invoperation and admits. of the ready discharge of any collected materialas and when required without the operator being underthe necessity ofreleasing the handle by means of which the .sweeper is propelled.

It is to be appreciatedthat in the case of magnetic separators usingfixed shields as in the embodiments illustrated and described withreference to Figures 1 the said shields may be made of either.magneticor nonmagnetic material although the use of non-magneticmaterial is to be preferred.

Further it is to be appreciated that when permanent magnets are employedas isthe case in all therembodiments illustrated, the magnets maybe ofthe fingeror solid or indented types {and may be built up of magnets ofthe same polarity or of alternating polarity.

In addition it, is to be appreciated that when permanent magnets areemployed the bulk of the magnets may be reduced by using inductor barsof a less expensive magnetic material thereby reducing the initial costwithout materially impairing the intensity of the effective magneticfield of force.

Moreover it is to bev appreciated that the, invention is .not limitedtomagnetic separators us1ng permanent magnets as it may be applied tomagnetic separators. using electro-magnets.

We claim:

1. A magnetic floor sweeper incorporating a cylindrical drum thelowermost portionof the outer, surface of which serves asthe collectingsurface for themagnetic material tobe collected, wheeled supportingmeans for said drum, handle means for propelling the drum over the floorfrom which magnetic material is to be collected, magnetic v wardlyprojecting force producing means located within said drum With themagnetic poles located normally in proximity to the inner surface of thelowermost portion of the drum, means for turning the said magnetic forceproducing means from the position occupied during sweeping so that anymagnetic material collected on the drum can follow. the magnetic forceproducing means as it is turned, and means for arresting the movement ofthe collected materialafter the magnetic force producing means has beenturned to a predetermined extent so that after the collected materialhas reached the arresting position continued turning of the magneticforce producing means results in the collected material being subjectedto a diminishing field of force whereby the collected material isreleased for collection or disposal.

2; A' magnetic floor sweeper incorporating a cylindrical drum thelowermost portion of the outer surface of which serves as the collectingsurface for the magnetic material to be collected, a supported meansdisposed axially within said drum and turnable relatively thereto, saidsupporting means having outwardly'projecting portions at each endthereof, wheels mounted on the outportions of the supporting means,handle means for propelling the drumover the floor from which magneticmaterial is to be collected, magnetic force producing means fixed to anddepending from the supporting means aforesaid with the magnetic poleslocated normally in proximity to the inner surface of the lowermostportion'of the drum, means for turning the said magnetic force producingmeans from the position occupied during sweeping so that any magneticmaterial collected on the drum can follow the magnetic force producingmeans as it is turned, and means for arresting the movement of thecollected material after the magnetic force producing means has beenturned to a pre-determined extent so that after the collected materialhas reached the arresting position continued turning of the magneticforce producing means results in the collected material being subjectedto a diminishing of the field of force whereby the collected material isreleased for collection or disposal.

3. A magnetic floor sweeper incorporating a cylindrical drum thelowermost portion of the outer surface of which serves as the collectingsurface for the magnetic material to becollected, a supporting meansdisposed axially within the said drum and turnable relatively thereto,the said supporting means having outwardly projecting portions at eachend thereof, wheels mounted on the outwardly projecting portions of thesupporting means, handle means for propelling the drum over the fioorfrom which magnetic material is to be collected, one way clutch meansfor connecting the wheels to the supporting means, said one way clutchmeans permitting the wheels to turn freely on the outwardly pro--.jecting portions of the supporting means when the sweeper is propelledforwardly but connecting. the wheels to the supporting means when thesweeper is drawn backwardly so that the supporting means turns with thewheels when the sweeper is drawn backwardly, magnetic force producingmeans fixed to and depending .from the supporting means with themagnetic poles locatednormally inproximity to the inner surface of thelowermost portion of the drum, and arresting means for the collectedmaterial located at the rear of the drum whereby when the sweeper isdrawn rearwardly with a consequential turning of the magnetic forceproducing means any collected magnetic material follows the magneticforce! producing'means as it turns until arrested by the arresting meansso that as the magnetic field diminishes with continued movement of themagnetic force producing means away from the arresting means thecollected material is released for collection or disposal.

4. A. magnetic floor sweeper incorporating a cylindrical drum thelowermost portion of the outer surface ,of which serves as thecollecting surface for the magnetic material to be collected, asupporting means disposed axially within said drum and turnablerelatively thereto,

said supporting means having outwardly projecting portions at each endthereof, wheels freely mounted on the outwardly projecting portions ofthe supporting means, handle means for propelling the drum over thefloor from which magnetic material is to be collected, magnetic forceproducing means fixed to and depending from the supporting means withthe magnetic poles located normally in proximity to the inner surface ofthe lowermost portion of the drum, a longitudinal bar located in frontof the separator and connected to the supporting means whereby themagnetic force producing means can be turned from the position occupiedduring sweeping so that any magnetic material collected on the drum canfollow the magnetic force producing means as it is turned, said barserving also as a bumper, and a longitudinal projecting means arrangedon the outer periphery of the drum which serves to arrest the movementof the collected material after the magnetic force producing means hasbeen turned to an extent so that after the collected material isarrested by the said longitudinal projecting means continued turning ofthe magnetic force producing means results in the collected materialbeing subjected to a diminishing field of force whereby the collectedmaterial is released for collection or disposal.

5. A magnetic floor sweeper incorporating a cylindrical drum thelowermost portion of the outer surface of which serves as the collectingsurface for the magnetic material to be collected, a supporting meansdisposed axially within said drum and turnable relatively thereto, saidsupporting means having outwardly projecting portions at each endthereof, wheels mounted on the outwardly projecting portions, of thesupporting means, handle means for propelling the drum over the floorfrom which magnetic material is to be collected, one way clutch meansfor connecting the wheels to the supporting means, said one way clutchmeans permitting the wheels to turn freely on the outwardly projectingportions of the supporting means when the sweeper is propelledforwardly, but connecting the wheels to the supporting means when thesweeper is drawn backwardly so that the supporting means turns with theWheels until the collected material attains the position occupied by thescraper edge and whereby the continued movement of the magnetic forceproducing means after the collected material has been arrested by thescraper edge results in the collected material being subjected to adiminishing field of force so that the collected material is forced anddischarged into the collecting receptacle.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 148,517 Smith Mar. 10, 1874 1,326,561 Ady Dec. 30, 19191,425,235 Bradley Aug. 8, 1922 1,630,987 Turner May 31, 1927 2,258,194Queneau Oct. 7, 1941 2,426,795 Sjostrom Sept. 2, 1947 2,455,319 StearnsNov. 30, 1948 2,461,008 Stearns Feb. 8, 1949 2,502,096 Kotilinek Mar.28, 1950 2,564,515 Vogel Aug. 14, 1951

